sparsediag is the code to use in this case




On Aug 26, 2014, at 8:41, "bonanjiang@gmail.com" <bonanjiang@gmail.com> wrote:

Hi, all
I currently tend to calculate the energy of the lowest 4 states of a fermion system with fulldiag of ALPS. However, since the system has 12 eigenstates in total and fulldiag gives all of them, the time it takes is a little bit long. So, my question is: is there any way to limit the number of eigenstates that fulldiag calculates? for example, the lowest 4 states.  
 
Bo-Nan